31. In 1967 a trip to the lock showed it unnavigable , but in reasonable condition. 32. Rocks and rapids make both unnavigable , but much timber goes down the Nam Hsim. 33. On the western end of Lake Erie, water levels fell to unnavigable levels near Cleveland. 34. But the trems $ reeds and filth that collect here make this section unnavigable and smelly. 35. Their violence when they are full makes them difficult to control, and they are unnavigable . 36. The Platte proved to be unnavigable . 37. Due to changes in the shape of the tunnel over time, the tunnel became unnavigable . 38. Closed since Tuesday, the Ship Channel is virtually unnavigable , said Coast Guard spokesman Marty Paul. 39. Streep actually learned to navigate Class V rapids, the category just below the level deemed unnavigable . 40. Most of the rivers in Yunnan are unnavigable , except for short distances or in broken stretches.
